Chapter 8 Post Test Worksheet
Name: _______________________
Period: ______
1. Complete the table below for regular polygons by filling in the blank with one of the
following: increases, decreases, does not change.
As the
number of
sides
The sum of
the interior
angles
The measure
of one
interior angle
The sum of
the exterior
angles
The measure The measure
of one
of one
exterior angle central angle
Increases
Decreases
Increases
Increases
Decreases
Show your work for all of the following problems
2.
Calculate the sum of the measures of the interior angles of a 95-gon.
3.
Use the theorems for interior and exterior angles of a polygon to find:
a) the measure of each exterior angle in a regular 12-gon (dodecagon).
b) the number of sides of an n-gon if the sum of the interior angles is 2520˚.
c) the number of sides of a regular n-gon if one exterior angle measures 20˚
d) the number of sides of a regular n-gon if one interior angle measures 170˚.
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Chapter 8 Post Test Worksheet
4.
Find x and/or y.
a.
b.
142
84
2x
2x
x
110
c.
5x
4x + 2
5x + 6
x – 10
2y
3x + 5
2x – 2
d.
(x + 14)
+
64
x
e.
150
(x + 10)
+
x
5.
If each exterior angle on a regular polygon has a measure of 12, how many sides will the
polygon have?
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Chapter 8 Post Test Worksheet
6.
Find the area of the region where the congruent
regular hexagons overlap.
32’
7. Draw and label a regular hexagon, then find the area of the regular hexagon with an apothem length
of 6 cm.
8. Draw and label a regular octagon, then find the area of the regular octagon with a radius of 9 cm.
9. The area of a triangle is 17 in2. How tall is the triangle if the base is 4 inches?
10. The area of the triangle is 302.6 cm2. If the height is 7 cm, calculate the length of the base to
the nearest tenth of a cm.
11. Find the length of AB when the area of the triangle ABC is 95.7 mm2. Round answer to
nearest 0.1 mm.
A
10 mm
B
NTHS 2012-2013
C
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Chapter 8 Post Test Worksheet
ANSWER KEY SO YOU CAN CHECK YOUR WORK. Be sure you show how you calculated
your answers!
1. Complete the table below for regular polygons by filling in the blank with one of the
following: increases, decreases, does not change.
As the
number of
sides
The sum of
the interior
angles
The measure
of one
interior angle
The sum of
the exterior
angles
The measure The measure
of one
of one
exterior angle central angle
Increases
Increases
Increases
Decreases
Decreases
Decreases
Decreases
Decreases
Increases
Increases
Increases
Increases
Increases
Decreases
Decreases
Decreases
Decreases
Decreases
Increases
Increases
Decreases
Decreases
Decreases
Does not
change
Does not
change
Does not
change
Does not
change
Does not
change
Increases
Increases
Show your work for all of the following problems
2.
Calculate the sum of the measures of the interior angles of a 95-gon.
[16,740°]
3.
Use the theorems for interior and exterior angles of a polygon to find:
a) the measure of each exterior angle in a regular 12-gon (dodecagon).
[30°]
b) the number of sides of an n-gon if the sum of the interior angles is 2520˚.
[16 sides]
c) the number of sides of a regular n-gon if one exterior angle measures 20˚
[18 sides]
d) the number of sides of a regular n-gon if one interior angle measures 170˚.
[36 sides]
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Chapter 8 Post Test Worksheet
4.
Find x and/or y.
a.
b.
142
84
2x
2x
x
110
[a. x = 38°; b. x = 64°]
c.
5x
4x + 2
5x + 6
x – 10
2y
3x + 5
2x – 2
[x = 35.95°; y = 72.025°]
d.
(x + 14)
+
64
x
d. [x ≈ 106.7]
e.
150
e. [x ≈ 117.5]
(x + 10)
+
x
5.
If each exterior angle on a regular polygon has a measure of 12, how many sides will the
polygon have?
[30 sides]
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Chapter 8 Post Test Worksheet
6.
Find the area of the region where the congruent
regular hexagons overlap.
32’
[128√𝟑 ≈ 221.7 𝒊𝒏𝟐 ]
7. Draw and label a regular hexagon, then find the area of the regular hexagon with an apothem length
of 6 cm.
[≈ 124.7 𝒄𝒎𝟐 ]
8. Draw and label a regular octagon, then find the area of the regular octagon with a radius of 9 cm.
[≈ 229.1 𝒄𝒎𝟐 ]
9. The area of a triangle is 17 in2. How tall is the triangle if the base is 4 inches?
[8.5 𝒊𝒏 ]
10. The area of the triangle is 302.6 cm2. If the height is 7 cm, calculate the length of the base to
the nearest tenth of a cm.
[86.5 cm]
11. Find the length of AB when the area of the triangle ABC is 95.7 mm2. Round answer to
nearest 0.1 mm.
A
[21.2 mm]
10 mm
B
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C
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